1.
What type of cells produce myelination for central axons?
Correct Answer
B. Oligodendrocytes
Explanation
Oligodendrocytes are the type of cells that produce myelination for central axons. Schwann cells, on the other hand, produce myelination for peripheral axons. Schwannoma is a type of tumor that arises from Schwann cells. Therefore, the correct answer is Oligodendrocytes.
2.
What type of brain cells produce myelin sheath for
Correct Answer
D. Both A and B
Explanation
The type of brain cells that produce the myelin sheath are:
Schwann cells
Oligodendrocytes
Schwann cells are primarily found in the peripheral nervous system and are responsible for the myelination of peripheral nerves. Oligodendrocytes, on the other hand, are located in the central nervous system (which includes the brain and spinal cord) and they myelinate the axons in the CNS.
Glial cells is a broader category that includes various types of cells, such as astrocytes, microglia, oligodendrocytes, and others involved in supporting and protecting neurons. Since oligodendrocytes are a type of glial cell, this answer could also be considered correct in a broader sense, but more specific choices like Schwann cells and oligodendrocytes directly address the production of the myelin sheath.
3.
The brain functions that are related to hearing belong to which lobe?
Correct Answer
A. Temporal
Explanation
The brain functions related to hearing belong to the temporal lobe. The temporal lobe is responsible for processing auditory information and is located on the sides of the brain, just above the ears. It plays a crucial role in interpreting sounds, recognizing speech, and perceiving music. Additionally, the temporal lobe is also involved in memory formation and language comprehension.
4.
Approximately how many layers are there in the human neocortex?
Correct Answer
C. 6
Explanation
The human neocortex consists of approximately six layers. These layers are responsible for different functions, such as processing sensory information, motor control, and higher cognitive functions. Each layer contains different types of neurons and connections, which allow for complex information processing and integration.
5.
The gaps in myelinated axons are known as what?
Correct Answer
A. Nodes of Ranvier
Explanation
The gaps in myelinated axons are known as nodes of Ranvier. These nodes are small, unmyelinated sections of the axon that are crucial for the conduction of nerve impulses. They allow the electrical signal to jump from one node to another, which speeds up the transmission of the signal along the axon. This process, known as saltatory conduction, helps to conserve energy and increase the efficiency of nerve impulse transmission. Therefore, the correct answer is Nodes of Ranvier.
6.
Which of the following is a demyelinating disease?
Correct Answer
C. Multiple Sclerosis (MS)
Explanation
Multiple Sclerosis (MS) is a demyelinating disease because it involves the destruction of the protective covering (myelin) that surrounds nerve fibers in the central nervous system. This demyelination disrupts the normal flow of electrical impulses along the nerves, leading to various neurological symptoms such as muscle weakness, coordination problems, and cognitive impairments. Migraine, meningitis, and schizophrenia are not demyelinating diseases as they do not involve the destruction of myelin.
7.
Which area of the human brain has the highest density of neurons?
Correct Answer
B. Cerebellum
Explanation
The cerebellum is the area of the human brain that has the highest density of neurons. It is responsible for coordinating voluntary movements, balance, and posture. The cerebellum contains about 69 billion neurons, which is more than any other area of the brain. These neurons are densely packed and organized in a highly structured manner, allowing for precise control and coordination of movement. Additionally, the cerebellum plays a role in cognitive functions such as attention, language, and learning.
8.
What is the function of the myelin sheath in the brain?
Correct Answer
D. All of the above
Explanation
The myelin sheath in the brain serves multiple functions. Firstly, it helps in saltatory conduction of the impulses, which means that it allows the electrical impulses to travel faster and more efficiently along the nerve cells. Secondly, it acts as a protective layer for the nerve cells, shielding them from damage and maintaining their integrity. Lastly, the myelin sheath helps maintain the strength of the electrical impulses in the brain, ensuring that they are transmitted accurately and effectively. Therefore, all of the given options are correct.
9.
What is the color of myelin?
Correct Answer
B. White
Explanation
Myelin is a substance that covers and protects nerve fibers in the central nervous system. It is made up of fats and proteins, and its color is white. This is because myelin is mostly composed of lipids, which are white in color. The white color of myelin allows for efficient transmission of electrical signals along the nerve fibers.
10.
The thick band of myelinated axons that connects the hemispheres is known as what?
Correct Answer
D. Corpus callosum
Explanation
The thick band of myelinated axons that connects the hemispheres of the brain is known as the corpus callosum. It plays a crucial role in facilitating communication and coordination between the two hemispheres, allowing them to work together in various cognitive and motor functions.